From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 7C1D528C5B1; Sun, 30 Aug 2026 23:53:24 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1788134005; cv=none; b=htX0qpZyWMcFiOMTwkIztnZZaDVJldtbiUXZaXu0goQOthTDxotSgn9GfcEP49kEjBqovrzXxyTCnU4CirmrA8zCHVFxXsVYAYbqQAitc6dbN0XfX4h3Ucn1PlxxHVtOg9urhJGt5n2/NtPjS27flzprEB/upO7Ya7uVDNTAxH4= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1788134005; c=relaxed/simple; bh=AgjI3O4F+GubT2JSQCY8Tpl0l3FNASSfQaXUdw4rbuY=; h=Date:From:To:Cc:Subject:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=heHEaPNQq5ImooiyZVOmAlqgXGMx1QyCTglwyn+SrwIviR7eKL9EnVvmEJrXYCq2WHAwPVJOu+Foc9bzMeP3f85yFLWZqz90UANP7AAHY3XyCaOk3k+e1m5ME+zRjlYPtANyK87VIra2xjrOWBH7Q+sY9I5vct2TAPy03/n5rAQ= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=Cy1bWdma; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="Cy1bWdma" Received: by smtp.kernel.org (Postfix) with ESMTPSA id ED00E1F000E9; Sun, 30 Aug 2026 23:53:22 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1788134004; bh=ldpcUbAWpGoUTXYsH8TqTNY0l9FCJaJkj70LvsUK7wM=; h=Date:From:To:Cc:Subject:In-Reply-To:References; b=Cy1bWdmaNA1Z0aY0ArkK40kYsap+W135sn35yRmmBcCLq98pm4LUeEHfEeVUzCvhZ WoJjPrpZZnOygPq9GjjuEW/D3zq/3U14mlbURSXxuAYhYymmGmTaPVXedbsT8Y9rVP 1fB0irasgk9moHOYu5MtX32VLo8+d0+AdrampQXaeO8Xq7Y3MpHkt8CNIlFF6RBlYB hh9Uax+2aaPkGEmhnXgCec12xCQ7g41E8K51g0l8Wjg1UKjPNSXxf/MA9/qoTSVtzQ WUqchdGPx7YyKR50+Iv38JGayCohdKy8HNE2dI1hF2eAWkLus4BZgYBWG09vEP/pv+ oQy9m0ItxGZVA== Date: Mon, 31 Aug 2026 00:53:17 +0100 From: Jonathan Cameron To: Antoniu Miclaus Cc: Nuno =?UTF-8?B?U8Oh?= , Michael Hennerich , David Lechner , , , Subject: Re: [PATCH] iio: adc: ad4080: allow debugfs register access to both channels Message-ID: <20260831005317.41cf75a1@jic23-huawei> In-Reply-To: <20260826111613.14218-1-antoniu.miclaus@analog.com> References: <20260826111613.14218-1-antoniu.miclaus@analog.com> X-Mailer: Claws Mail 4.4.0 (GTK 3.24.52; x86_64-pc-linux-gnu) Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit On Wed, 26 Aug 2026 14:16:13 +0300 Antoniu Miclaus wrote: > The dual-channel parts (AD4880/AD4883/AD4884) are built from two > independent ADC dies, each with its own SPI chip select and register > map. They are presented as a single IIO device because the FPGA > interleaves both dies into one DMA stream, so only one direct_reg_access > debugfs file is created and it can only reach channel A's regmap. Channel > B's registers are therefore inaccessible, which blocks bring-up and > debugging of the second die. > > Select the target die through the debugfs register address: the low 8 > bits are the register offset and the upper bits are the channel index > (0x0nn selects channel A, 0x1nn channel B). A read returns the real > register value of the selected die and each die is addressed > independently; single-channel parts only accept channel 0. > > Signed-off-by: Antoniu Miclaus Applied to the testing branch of iio.git thanks, Jonathan